Fossil fuels contribute at least 90% of the present energy demand. However, the fossil fuels are consumable materials which cannot be regenerated once used, are limited in quantity and extremely harmful to the environment due to pollution substances such as carbon dioxide gas generated during combustion, thus raising significant environmental problems.
Hydrogen energy is attracting increasing interest as a new and clean energy resource capable of replacing fossil fuels, in particular, hydrogen is a material greatly coming into the spotlight as an alternative energy source while fossil fuels are being rapidly exhausted. Hydrogen energy has various benefits such as high energy efficiency to mass, water generated as the only residue, etc., thus satisfying advantageous conditions for a future fuel.
However, for use of hydrogen, it is necessary to use a specific medium for safe storage and delivery of hydrogen. Although massive research and investigations have been conducted to solve this problem, there is still no proposal for an ideal solution satisfying requirements suggested by the US department of energy (DOE).
Additionally, a variety of studies for formation of metal nanoparticles have been conducted, including, for example, that using block copolymers resulting in formation of metal nanoparticles such as iron oxide (Fe3O4)(B. Y. Sohn et al., J. Ame. Chem. Soc. 125, 6368, 2003), gold (J. P. Spatz et al., Langmuir 16, 407, 2000), titanium oxide (X. Li, et al., Langmuir 21, 5212, 2005) and the like. However, there is still a need for the development of novel methods to apply the metal nanoparticles formed above in the production of hydrogen.